I feel that Nvidia cheaped out yet again, such as how long it took them to move to GDR5 ram. With a 256bit controller it let them move from 1.5GB to 2GB instead of jumping to 3GB.
NV didn't cheap out. It used a mid-range GK104 chip to go head-to-head against AMD's 7970. The fact that a 294mm^2 256-bit bus NV chip trades blows with AMD's 384-bit bus chip is incredible. This wasn't actually planned. If anything it shows 2 things:
1) AMD sacrificed a great deal of transistor efficiency by incorporating GPGPU features;
2) AMD's HD7900 series is not very well balanced (possibly pixel fillrate limited) for games. This is more evident when comparing it to Pitcairn.
Also, while GK104 has 2GB of VRAM, it has
stronger tessellation and texture performance. Both of those factors imo will show up in future games before 3GB of VRAM becomes a factor. Any next generation game that will actually
need 3GB of VRAM will send HD7900/GTX680 series on vacation. At this current state for games Kepler has no real weaknesses. GTX670/680 have weaknesses but nothing that can't be addressed with more SPs and larger memory bus. GCN on the other hand is 1 generation behind as an architecture for games since a mid-range Kepler chip can easily go against AMD's 365mm^2 chip. AMD has had the performance/watt and performance/transistor locked in for a long time. Not anymore. That's bad news for their engineers. If NV manages to manufacture a large die Kepler chip, it's lights out for GCN 1.0.
In pretty much all the modern games from SKYRIM, BF3, Crysis 2, Dirt 3 to Batman AC, NV's Kepler does great. That puts HD7900 series in worse position since hardly anyone is making games on Crysis 1 / Warhead or Metro 2033 game engines. For 2560x1600 and above a single HD7970 isn't fast enough for games that actually need the extra performance (Metro 2033, Witcher 2).
Crytek is already working on adding dynamic tessellation into Crysis 3.
Even more tessellation is bad news for AMD since they are lagging behind in this area. Dirt 3 performance should also translate into better Kepler performance in future games from Codemasters. BF3 has 2 more expansions coming this year. In all of those games GTX680 should continue to hold an advantage over 7970 and GTX670 will simply crush 7950 series.
AMD better hope GK110 is 12 months away and TSMC continues having capacity issues for another 6 months. If capacity picks up in the next 2 months and GTX670 starts dropping to $350 with rebates, it would be game over for HD7870/7950 and 7970.
Not sure how accurate or if a marketing stunt, but Tim Sweeney has stated that only Kepler is fast enough to run
Unreal Engine 4 games. Based on all of this, I can't see how HD7970 is more future proof.